Substituted phenols as stabilizers

ABSTRACT

Novel compositions are described which comprise an elastomer or a lubricant and at least one compound of the formulae I or II ##STR1## The symbols R 1 , R 2 , R 3 , Z 1  and Z 2  are as defined in claim 1. 
     The compounds of the formula II and some of the compounds of the formula I are novel, and they are used especially as antioxidants.

This is a divisional of application Ser. No. 136,686 filed on Dec. 22,1987, now abandoned, and a continuation of application Ser. No. 578,926,filed Sep. 6, 1990, now abandoned.

The present invention relates to compositions comprising substitutedbis-(mercaptomethyl)-phenols as stabilizers and to novelbis-(mercaptomethyl)-phenols.

Phenols containing mercaptomethyl are known as stabilizers. Thus, forexample, several bis-(mercaptomethyl)-phenols are listed in U.S. Pat.No. 2,417,118, but without precise data on the substituted sites on thephenol. These phenols are suitable as additives for lubricants,especially in engine oils.

U.S. Pat. No. 3,227,667 has disclosed2,6-bis-(alkoxycarbonylalkylenethiomethyl)-4-alkylphenols asantioxidants for polyolefins.

According to EP-A-0,165,209, 2,4-bis-(mercaptomethyl)-6-alkylphenols,for example, are suitable as stabilizers for organic polymers andlubricants.

Several specific 2,6-bis-(mercaptomethyl)-phenols are also known asintermediates, for example 2,6-bis-(ethylthiomethyl)-4-methylphenol(DE-Al-2,838,273), 2,6-bis-(butylthiomethyl)-4-methylphenol [I. W.Rudermann and E. M. Fettes, J. Am. Chem. Soc. 71 (1949), 2264] as wellas 2,6-bis-(phenylthiomethyl)- and2,6-bis-(benzylthiomethyl)-4-methylphenol [Abdullaeva, C. A. volume 83(1975), 79881 h].

There is still a demand for effective stabilizers for materials whichare sensitive to thermal, oxidative or light-induced degradation.

The invention therefore relates to a composition comprising an elastomeror a lubricant and at least one compound of the formulae I or/and II##STR2## in which the radicals R₁ are identical or different andindependently of one another are C₁ -C₂₀ -alkyl which is unsubstitutedor substituted by 1 or 2 hydroxyl groups or/and interrupted by --O--, orare C₁ -C₄ -alkylene-COOR₂ ', C₁ -C₄ -alkylene-CO-NR₂ "R₄, C₅ -C₁₂-cycloalkyl, phenyl, 1-naphthyl, 2-naphthyl, C₁ -C₄ -alkylphenyl orphenyl-C₁ -C₄ -alkyl, R₂, R₂ ' and R₂ " independently of one another areC₁ -C₂₀ -alkyl, allyl, methylallyl, propargyl, C₅ -C₁₂ -cycloalkyl,phenyl or benzyl, R₃ is hydrogen, C₁ -C₂₀ -alkyl, C₂ -C₁₈ -alkenyl orhalogen, R₄ is hydrogen, C₁ -C₂₀ -alkyl or C₂ -C₁₈ -alkenyl, Z₁ is --S--or --C(Z₃)(Z₄)-- and Z₂ is hydrogen, C₁ -C₂₀ -alkyl or --CH₂ --S-- R₁,Z₃ and Z₄ independently of one another being hydrogen or methyl, withthe proviso that the phenols of the formula II are free of the --CH₂--S--R₁ functional group in the m-position relative to the OH group.

Examples of C₁ -C₂₀ -alkyl R₁, R₂, R₂ ', R₂ ", R₃, R₄ and Z₂ are methyl,ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl,isopentyl, n-hexyl, 1,1-dimethylbutyl, n-heptyl, n-octyl, 2-ethylhexyl,n-nonyl, n-decyl, 1,1,3,3-tetramethylbutyl, 1,1,3,3-tetramethylhexyl,n-undecyl, n-dodecyl, 1,1,3,3,5,5-hexamethylhexyl,2,2,4,6,6-pentamethylhept-4-yl, n-tetradecyl, n-hexadecyl, n-octadecylor n-eicosyl.

R₁ is preferably straight-chain C₈ -C₂₀ -alkyl, especially C₈ -C₁₂-alkyl, for example n-octyl, n-decyl or n-dodecyl.

R₂, R₂ ' and R₂ " are preferably methyl ethyl or branched C₃ -C₂₀-alkyl, for example isopropyl, t-butyl, t-amyl, 2-ethylhexyl,1,1,3,3-tetramethylbutyl, 1,1,3,3-tetramethylhexyl or1,1,3,3,5,5-hexamethylhexyl and especially methyl, t-butyl, 2-ethylhexyland 1,1,3,3-tetramethylbutyl.

C₁ -C₂₀ -Alkyl R₁ substituted by one or two hydroxyl groups is, forexample, hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl, 2-hydroxybutyl,2-hydroxyhexyl, 2-hydroxyoctyl, 2-hydroxydecyl, 2-hydroxydodecyl,2-hydroxytetradecyl, 2-hydroxyhexadecyl, 2-hydroxyoctadecyl,2-hydroxyeicosyl or 2,3-dihydroxypropyl. C₁ -C₄ -Hydroxyalkyl, forexample 2-hydroxypropyl or 2,3-dihydroxypropyl and especially2-hydroxyethyl are preferred.

Alkyl R₁ interrupted by --O-- can have one or more, for example 1 to 6,and especially 1 or 2 --O-- interruptions and is, for example,3-oxapropyl, 3-oxabutyl, 3-oxapentyl, 3,6-dioxaheptyl, 3,6,9-trioxadecylor 3,6,9,12,15,18-hexaoxanonadecyl.

C₂ -C₁₈ -Alkenyl R₃ and R₄ are, for example, vinyl, allyl, but-3-enyl,pent-4-enyl, hex-5-enyl, oct-7-enyl, dec-9-enyl, dodec-11-enyl oroctadec-17-enyl. Vinyl or allyl are preferred.

C₅ -C₁₂ -Cycloalkyl R₁, R₂, R₂ ' and R₂ " are, for example cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl or cyclododecyl. C₅ -C₇ -Cycloalkyl, and very particularlycyclohexyl in the case of R₁, are preferred.

Phenyl C₁ -C₄ -alkyl R₁ is, for example, benzyl, phenylethyl,α-methylbenzyl or α,α-dimethylbenzyl. Benzyl is preferred.

C₁ -C₄ -Alkylphenyl R₁ can have, for example, 1 to 3, especially 1 or 2alkyl groups and is, for example, o-, m- or p-tolyl, 2,4-, 2,6-, 3,5- or3,6-dimethylphenyl, ethylphenyl, propylphenyl, isopropylphenyl,t-butylphenyl or di-t-butylphenyl. Tolyl is preferred.

Halogen R₃ is, for example, chlorine or bromine, especially chlorine.

Those compositions are preferred which contain an elastomer and at leastone compound of the formulae I or/and II.

Compositions containing a lubricant and at least one compound of theformulae I or/and II, wherein R₂ is methyl, ethyl or branched C₃ -C₂₀-alkyl, allyl, methylallyl, propargyl or benzyl and R₁, R₃, Z₁ and Z₂are as defined above, are also preferred.

Those compositions are of particular interest which contain an elastomeror a lubricant and at least one compound of the formula I or/and II,wherein the radicals R₁ are identical or different and independently ofone another are C₈ -C₂₀ -alkyl or C₁ -C₄ -alkylene-COOR₂ ', R₂ and R₂ 'being C₁ -C₂₀ -alkyl, Z₁ is --CH₂ -- or --C(CH₃)₂ -- and Z₂ is asdefined above.

Those compositions are particularly preferred which contain an elastomeror a lubricant and at least one compound of the formula I, wherein theradicals R₁ independently of one another are unsubstituted C₈ -C₂₀-alkyl groups or are C₁ -C₂₀ -alkyl groups which are substituted by 1 or2 hydroxyl groups, and those compositions are very particularlypreferred in which the radicals R₁ are identical and especially are C₈-C₁₂ -alkyl groups.

Those compositions are of particular importance which contain anelastomer or a lubricant and at least one compound of the formula IIa##STR3## in which R₁, R₃, Z₁ and Z₂ are as defined above, and especiallythose compositions in which R₃ is hydrogen and Z₁ is --C(Z₃)(Z₄)--, Z₃and Z₄ being as defined above.

Those compositions are very particularly preferred which contain acompound of the formula IIa, in which Z₂ is the --CH₂ --S--R₁ radical.

The substances listed below are to be regarded as representativeexamples of compounds of the formulae I and II, which can be present inthe compositions according to the invention:2,6-bis-(2'-hydroxyethylthiomethyl)-4-methylphenol,2,6-bis-(2',3'-dihydroxypropylthiomethyl)-4-methylphenol,2,6-bis-(2'-methylaminocarbonylethylthiomethyl)-4-phenylphenol,2,6-bis-(N,N-diethylaminocarbonyl-ethylthiomethyl)-4-allyl-phenol,2,6-bis-(n-octylthiomethyl)-4-methylphenol,2,6-bis-(t-octylthiomethyl)-4-t-butyl-phenol¹,2,6-bis-(t-dodecylthiomethyl-4-t-octyl-phenol²,2,6-bis-(benzylthiomethyl)-6-methylphenol,2,6-bis-(phenylthiomethyl)-4-t-butyl-phenol,2,6-bis-(2'-ethylhexyloxycarbonylmethyl-thiomethyl)-4-cyclohexyl-phenol,2,6-bis-(n-octadecyloxycarbonylmethyl-thiomethyl)-4-propargyl-phenol,2,6-bis-[2'-(2"-ethylhexyloxycarbonyl)-ethylthiomethyl]-4-t-butylphenol,2,2-bis-[4',4"-dihydroxy-3',3",5',5"-tetrakis-(octylthiomethyl)-phenol]-propane,2,2-bis-]4',4"-dihydroxy-3',3",5',5"-tetrakis-(dodecylthiomethyl)-phenyl]-methaneandbis-[4',4"-dihydroxy-3',3",5',5"-tetrakis-(2-ethylhexyloxycarbonylmethylthiomethyl)-phenyl]thioether.

As elastomer, the compositions according to the invention can contain,for example, the following materials:

1. Polydienes, for example polybutadiene, polyisoprene orpolychloroprene; block polymers, for example styrene/butadiene/styrene,styrene/isoprene/styrene or acrylonitrile/butadiene copolymers.

2. Copolymers of monoolefins and diolefins with one another or withother vinyl monomers, for example ethylene/alkyl acrylate copolymers,ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetatecopolymers, and terpolymers of ethylene with propylene and a diene suchas hexadiene, dicyclopentadiene or ethylidenenorbornene.

3. Halogen-containing polymers, for example polychloroprene, chlorinatedrubber, chlorinated or chlorosulfonated polyethylene, epichlorohydrinhomopolymers and copolymers, chlorotrifluoroethylene copolymers,polymers of halogen-containing vinyl compounds, for examplepolyvinylidene chloride, polyvinylidene fluoride, and copolymersthereof, such as vinyl chloride/vinylidene chloride, vinylchloride/vinyl acetate or vinylidene chloride/vinyl acetate. p1 4.Polyurethanes derived from polyethers, polyesters and polybutadienehaving terminal hydroxyl groups on the one hand and aliphatic oraromatic polyisocyanates on the other hand, and their initial products.

5. Natural rubber.

6. Mixtures (polyblends) of the polymers listed above.

7. Aqueous emulsions of natural or synthetic rubbers, for examplenatural rubber latex or latices of carboxylated styrene/butadienecopolymers.

In some cases, these elastomers are in the form of latices and can bestabilized as such.

Those compositions are preferred which contain, as the elastomer, apolydiene such as polybutadiene rubber, a halogen-containing polymersuch as polyvinylidene fluoride or a polyurethane.

Advantageously, the compositions according to the invention contain0.01-10% by weight of compounds of the formulae I or/and II asstabilizers, relative to the elastomer or to the lubricant, especially0.05-5.0% by weight. Mixtures of these compounds can also be used.

Incorporation into the elastomers can be carried out, for example, bymixing in the substances of the formulae I or/and II, and ifappropriate, further additives by the methods customary in industry,before or during shaping, or by applying the dissolved or dispersedcompounds to the polymer, if appropriate with subsequent evaporation ofthe solvent. The compounds of the formulae I or II can also be added inthe form of a master batch, which contains these compounds, for example,in a concentration from 2.5 to 25% by weight, to the plastics to bestabilized.

The elastomer-containing compositions according to the invention can beused in the most diverse forms, for example as sheets and films, fibres,tapes, moulding compositions, profiles or as binders for surfacecoatings, adhesives or cements.

In practice, the elastomer-containing compositions according to theinvention can contain further additives, examples of these are:

1. Antioxidants

1.1 Alkylated monophenols, for example 2,6-di-t-butyl-4-methylphenol,2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butyl-4-ethylphenol,2,6-di-t-butyl-4-n-butylphenol, 2,6-di-t-butyl-4-isobutylphenol,2,6di-cyclopentyl-4-methylphenol,2-(α-methylcyclohexyl)-4,6-dimethylphenol,2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol and2,6-di-t-butyl-4-methoxymethylphenol.

1.2. Alkylated hydroquinones, for example,2,6-di-t-butyl-4-methoxyphenol, 2,5-di-t-butylhydroquinone,2,5-di-t-amylhydroquinone and 2,6-diphenyl-4-octadecyloxyphenol.

1.3. Hydroxylated thiodiphenyl ethers, for example2,2'-thio-bis-(6-t-butyl-4-methylphenol), 2,2'-thio-bis-(4-octylphenol),4,4'-thio-bis-(6-t-butyl-3-methylphenol) and4,4'-thio-bis-(6-t-butyl-2-methylphenol).

1.4. Alkylidene-bisphenols, for example2,2'-methylene-bis-(6-t-butyl-4-methylphenol),2,2'-methylene-bis-(6-t-butyl-4-ethylphenol),2,2'-methylene-bis-[4-methyl-6-(α-methylcyclohexyl)-phenol],2,2'-methylene-bis-(4-methyl-6-cyclohexylphenol),2,2'-methylene-bis-(6-nonyl-4-methylphenol),2,2'-methylene-bis-(4,6-di-t-butylphenol),2,2'-ethylidene-bis-(4,6-di-t-butylphenol),2,2'-ethylidene-bis-(6-t-butyl-4-isobutylphenol),2,2'-methylene-bis-[6-(α-methylbenzyl)-4-nonylphenol],2,2'-methylene-bis-[6-(α,α-dimethylbenzyl)-4-nonylphenol],4,4'-methylene-bis-(2,6-di-t-butylphenol),4,4'-methylene-bis-(6-t-butyl-2-methylphenol),1,1-bis-(5-t-butyl-4-hydroxy-2-methylphenyl)-butane,2,6-bis-(3-t-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol,1,1,3-tris-(5-t-butyl-4-hydroxy-2-methylphenyl)-butane,1,1-bis-(5-t-butyl-4-hydroxy-2-methylphenyl)-3-n-dodecylmercaptobutane,ethylene glycol-bis-[3,3-bis-(3'-t-butyl-4'-hydroxyphenyl)butyrate],bis-(3-t-butyl-4-hydroxy-5-methylphenyl)-dicyclopentadiene andbis-[2-(3'-t-butyl-2'-hydroxy-5'-methylbenzyl)-6-t-butyl-4-methylphenyl] terephthalate.

1.5. Benzyl compounds, for example1,3,5-tris-(3,5-di-t-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,bis-(3,5-di-t-butyl-4-hydroxybenzyl) sulfide, isooctyl3,5-di-t-butyl-4-hydroxybenzyl-mercaptoacetate,bis-(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) dithioltherephthalate,1,3,5-tris-(3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate,1,3,5-tris-(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate,dioctadecyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate and calciummonoethyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate.

1.6. Acylaminophenols, for example lauric acid 4-hydroxyanilide, stearicacid 4-hydroxyanilide,2,4-bis-octylmercapto-6-(3,5-di-t-butyl-4-hydroxyanilino)-s-triazine andoctyl N-(3,5-di-t-butyl-4-hydroxyphenyl)-carbonate.

1.7. Esters of β-(3,5-di-t-butyl-4-hydroxyphenyl)-propionic acid withmonohydric or polyhydric alcohols, for example methanol, octadecanol,1,6-hexanediol, neopentyl glycol, thiodiethylene glycol, diethyleneglycol, triethylene glycol, pentaerythritol, tris-(hydroxyethyl)isocyanurate and di-hydroxyethyl-oxamide.

1.8. Esters of β-(5-t-butyl-4-hydroxy-3-methylphenyl)-propionic acidwith monohydric or polyhydric alcohols, for example methanol,octadecanol, 1,6-hexanediol, neopentyl glycol, thiodiethylene glycol,diethylene glycol, triethylene glycol, pentaerythritol,tris-(hydroxyethyl) isocyanurate and di-hydroxyethyl-oxamide.

1.9. Amides of β-(3,5-di-t-butyl-4-hydroxyphenyl)-propionic acid, forexampleN,N'-bis-(3,5-di-t-butyl-4-hydroxyphenylpropionyl)-hexamethylenediamine,N,N'-bis-(3,5-di-t-butyl-4-hydroxyphenylpropionyl)-trimethylenediamineand N,N'-bis-(3,5-di-t-butyl-4-hydroxyphenylpropionyl)-hydrazine.

2. UV absorbers and light stabilizers

2.1. 2-(2'-Hydroxyphenyl)-benzotriazoles, for example the 5'-methyl,3',5'-di-t-butyl, 5'-t-butyl, 5'-(1,1,3,3-tetramethylbutyl),5-chloro-3',5'-di-t-butyl, 5-chloro-3'-t-butyl-5'-methyl,3'-sec.-butyl-5'-t-butyl, 4'-octoxy, 3',5'-di-t-amyl and3',5'-bis-(α,α-dimethylbenzyl) derivatives.

2.2. 2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy,4-octoxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and2'-hydroxy-4,4'-dimethoxy derivatives.

2.3. Esters of various substituted benzoic acids, for example4-t-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate,dibenzoylresorcinol, bis-(4-t-butylbenzoyl)-resorcinol,benzoylresorcinol, 2,4-di-t-butylphenyl 3,5-di-t-butyl-4-hydroxybenzoateand hexadecyl 3,5-di-t-butyl-4-hydroxybenzoate.

2.4. Acrylates, for example ethyl α-cyano-β,β-diphenylacrylate, isooctyα-cyano-β,β-diphenylacrylate, methyl α-carbomethoxycinnamate, methylα-cyano-β-methyl-p-methoxycinnamate, butylα-cyano-β-methyl-p-methoxycinnamate, methylα-carbomethoxy-p-methoxycinnamate andN-(β-carboxymethoxy-β-cyanovinyl)-2-methylindoline.

2.5. Nickel compounds, for example nickel complexes of2,2'-thio-bis-[4-(1,1,3,3-tetramethylbutyl)-phenol], such as the 1:1 or1:2 complexes, which may contain additional ligands such asn-butylamine, triethanolamine or N-cyclohexyl-diethanolamine, nickeldibutyldithiocarbamate, nickel salts of the monoalkyl esters of4-hydroxy-3,5-di-t-butyl-benzylphosphonic acid, such as the methyl orethyl esters, nickel complexes of ketoximes such as2-hydroxy-4-methyl-phenyl undecyl ketoxime and nickel complexes of1-phenyl-4-lauroyl-4-hydroxy-pyrazole, with or without additionalligands.

2.6. Sterically hindered amines, for examplebis-(2,2,6,6-tetramethylpiperidyl) sebacate,bis-(1,2,2,6,6-pentamethylpiperidyl) sebacate,bis-(1,2,2,6,6-pentamethylpiperidyl)n-butyl-3,5-di-t-butyl-4-hydroxybenzylmalonate, the condensation productof 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinicacid, the condensation product ofN,N'-bis-(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and4-t-octylamino-2,6-dichloro-1,3,5-s-triazine,tris-(2,2,6,6-tetramethyl-4-piperidyl) nitrilotriacetate,tetrakis-(2,2,6,6-tetramethyl-4-piperidyl)1,2,3,4-butanetetracarboxylate and1,1'-(1,2-ethanediyl)-bis-(3,3,5,5-tetramethylpiperazinone).

2.7. Oxalic acid diamides, for example 4,4'-dioctyloxyoxanilide,2',2-dioctyloxy-5,5'-di-t-butyloxanilide,2,2'-didodecyloxy-5,5'-di-t-butyloxanilide, 2-ethoxy-2'-ethyloxanilide,N,N'-bis-(3-dimethylaminopropyl)-oxamide,2-ethoxy-5-t-butyl-2'-ethyl-oxanilide and its mixtures with2-ethoxy-2'-ethyl-5,4'-di-t-butyloxanilide, and mixtures of o- andp-methoxy- and o- and p-ethoxy-disubstituted oxanilides.

3. Metal deactivators, for example N,N'-diphenyloxamide,N-salicylal-N'-salicyloylhydrazine, N,N'-bis-salicyloylhydrazine,N,N'-bis-(3,5-di-t-butyl-4-hydroxyphenylpropionyl)-hydrazine,3-salicyloylamino-1,2,4-triazole and bis-benzylidene-oxalodihydrazide.

4. Phosphites and phosphonites, for example triphenyl phosphite,diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris-(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl phosphite, distearylpentaerythritol diphosphite, tris-(2,4-di-t-butylphenyl) phosphite,diisodecyl pentaerythritol diphosphite, bis-(2,4-di-t-butylphenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite,tetrakis-(2,4-di-t-butylphenyl) 4,4'-diphenylene-diphosphonite and3,9-bis-(2,4-di-t-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane.

5. Peroxide-destroying compounds, for example esters ofβ-thiodipropionic acid, for example the lauryl, stearyl, myristyl ortridecyl esters, mercaptobenzimidazole or the zinc salt of2-mercaptobenzimidazole, zinc dibutyldithiocarbamate, dioctadecyldisulfide and pentaerythritol tetrakis-(β-dodecylmercapto)-propionate.

6. Polyamide stabilizers, for example copper salts in combination withiodides and/or phosphorus compounds and divalent manganese salts.

7. Basic costabilizers, for example melamine, polyvinylpyrrolidone,triallyl cyanurate, urea derivatives, hydrazine derivatives, amines,polyamides, polyurethanes, alkali metal or alkaline earth metal salts ofhigher fatty acids, for example calcium stearate, zinc stearate,magnesium stearate, sodium ricinoleate and potassium palmitate, antimonypyrocatecholate or zinc pyrocatecholate.

8. Nucleating agents, for example 4-t-butylbenzoic acid, adipic acid anddiphenylacetic acid.

9. Fillers and reinforcing agents, for example calcium carbonate,silicates, glass fibres, asbestos, talc, kaolin, mica, barium sulfate,metal oxides and hydroxides, carbon black and graphite.

10. Further additives, for example plasticizers, lubricants,emulsifiers, pigments, fluorescent brighteners, flameproofing agents,antistatic agents, blowing agents, waxes, oils or organic solvents.

As lubricants, the compositions according to the invention can containlubricants based on mineral oils or synthetic oils.

The appropriate lubricants are known to those skilled in the art and aredescribed, for example, in "Schmiermittel Taschenbuch [LubricantsHandbook]" (Huthig Verlag, Heidelberg, 1974).

Lubricant formulations according to the invention can, moreover, alsocontain further additives, which are added in order to improve certainuse properties, for example further antioxidants, metal passivators,rust inhibitors, viscosity index improvers, pour point depressants,dispersants/surfactants and anti-wear additives.

Examples of antioxidants can be taken from the list given above underitem 1 for elastomer-containing compositions.

Examples of further additives for the lubricant compositions accordingto the invention are:

Examples of amine-type antioxidants:N,N'-di-isopropyl-p-phenylenediamine,N,N'-di-sec-butyl-p-phenylenediamine,N,N'-bis-(1,4-dimethyl-phenyl)-p-phenylenediamine,N,N'-bis-(1-ethyl-3-methyl-pentyl)-p-phenylenediamine,N,N'-bis-(1-methyl-heptyl)-p-phenylenediamine,N,N'-diphenyl-p-phenylenediamine,N,N'-di-(2-naphthyl)-p-phenylenediamine,N-isopropyl-N'-phenyl-p-phenylenediamine,N-(1,3-dimethyl-butyl)-N'-phenyl-p-phenylenediamine,N-(1-methyl-heptyl)-N'-phenyl-p-phenylenediamine,N-cyclohexyl-N'-phenyl-p-phenylenediamine,4-(p-toluene-sulfonamido)-diphenylamine,N,N'-dimethyl-N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine,4-isopropoxydiphenylamine, N-phenyl-1-naphthylamine,N-phenyl-2-naphthylamine, octylated diphenylamine, 4-n-butylaminophenol,4-butyrylamino-phenol, 4-nonanoylamino-phenol, 4-dodecanoylamino-phenol,4-octadecanoylamino-phenol, di-(4-methoxy-phenyl)-amine,2,6-di-tert-butyl-4-dimethylamino-methylphenol,2,4'-diamino-diphenylmethane, 4,4'-diamino-diphenylmethane,N,N,N',N'-tetramethyl-4,4'-diamino-diphenylmethane,1,2-di-[(2-methylphenyl)-amino]-ethane, 1,2-di-(phenylamino)-propane,(o-tolyl)-biguanide, di-[4-(1',3'-dimethyl-butyl)-phenyl]-amine,tert-octylated N-phenyl-1-naphthylamine and a mixture of mono- anddi-alkylated tert-butyl-/tert-octyl-diphenylamines.

Examples of metal passivators are: for copper, for example: triazole,benzotriazole and derivatives of these, 2-mercaptobenzothiazole,2,5-dimercaptothiadiazole, salicylidene-propylenediamine and salts ofsalicylaminoguanidine.

Examples of rust inhibitors are:

a) organic acids, their esters, metal salts and anhydrides, for example:N-oleoyl-sarcosine, sorbitan monooleate, lead naphthenate,dodecenylsuccinic anhydride, alkenylsuccinic acid half esters and4-nonylphenoxyacetic acid.

b) Nitrogen-containing compounds, for example:

I. primary, secondary or tertiary aliphatic or cycloaliphatic amines andamine salts of organic and inorganic acids, for example oil-solublealkyl ammonium carboxylates.

II. Heterocyclic compounds, for example: substituted imidazolines andoxazolines.

c) Phosphorus-containing compounds, for example: amine salts ofphosphoric acid partial esters.

d) Sulfur-containing compounds, for example: bariumdinonylnaphthalenesulfonates and calcium petroleum-sulfonates.

Examples of viscosity index improvers are:

polymethacrylates, vinylpyrrolidone/methacrylate copolymers,polybutenes, olefin copolymers and styrene/acrylate copolymers.

Examples of pour point depressants are:

polymethacrylate and alkylated naphthalene derivatives.

Examples of dispersants/surfactants are:

polybutenylsuccinic acid imides, polybutenylphosphonic acid derivativesand basic magnesium, calcium and barium sulfonates and phenolates.

Examples of anti-wear additives are:

compounds containing sulfur and/or phosphorus and/or halogen, such assulfurated vegetable oils, zinc dialkyl dithiophosphates, tritolylphosphate, chlorinated paraffins and alkyl and aryl disulfides.

Some compounds of the formula I are known. Those compounds of formula Iwhich are novel and the compounds of the formula II are also subjects ofthe present invention.

The invention therefore also relates to compounds of the formulae Ia orII ##STR4## in which the radicals R' are identical or different andindependently of one another are C₈ -C₂₀ -alkyl or C₁ -C₂₀ -alkyl whichis substituted by 1 or 2 hydroxyl groups or/and interrupted by --O--, orare C₁ -C₄ -alkylene-CO--NR₂ "R₄, C₅ -C₁₂ -cycloalkyl, 1-naphthyl,2-naphthyl, C₁ -C₄ -alkylphenyl, α-methylbenzyl or α,α-dimethylbenzyl,R" is methyl, ethyl or branched c₃ -C₂₀ -alkyl, allyl, methallyl,propargyl or benzyl and R₁, R₂ ", R₃, R₄, Z₁ and Z₂ are as definedabove, with the proviso that the phenols of the formula II are free ofthe --CH₂ --S--R₁ functional group in the m-position relative to the OHgroup.

The possible definitions of R₁ and R₂ in the formula I, as already givenabove as examples and as being preferred, analogously apply also to R'and R" in the formula Ia. The same applies to the symbols R₁, R₂ ', R₃,R₄, Z₁ and Z₂.

Those compounds of the formula Ia are preferred in which the radicals R'are identical and, in particular, are C₈ -C₂₀ -alkyl.

Those compounds of formula Ia are also preferred in which R" is methyl,ethyl or branched C₃ -C₂₀ -alkyl. Moreover, those compounds of theformula II are preferred which are of the formula IIa ##STR5## in whichR₁, R₃, Z₁ and Z₂ are as defined above.

Those compounds of the formula IIa are particularly preferred in whichR₃ is hydrogen and Z₁ is --C(Z₃)(Z₄)--, Z₃ and Z₄ being as definedabove. Those compounds are very particularly preferred in which Z₂ isthe radical --CH₂ --S--R₁.

The known compounds and novel compounds of the formulae I, Ia and II areprepared by methods known per se, such as are described, for example, inEP-A-0,165,209 and in U.S. Pat. No. 3,227,677. However, they can also beobtained by reacting a phenol of the formulae III or IV ##STR6## inwhich R₂, R₃ and Z₁ are as defined above and Z₂₂ is hydrogen or C₁ -C₂₀-alkyl, with formaldehyde or a compound which releases formaldehydeunder the reaction conditions, and with at least one mercaptan R₁ --SHin the presence of a base, the base being mono-, di- or tri-methylamineor mono- or di-ethylamine.

Preferably, mono- or di-methylamine and especially dimethylamine areused. The base can be used, for example, in the form of a 10-35%solution in ethanol, methanol or other lower alcohols, or in the pureform. Dimethylamine can also be used as a gas. The base can be employed,for example, in a quantity of 1-50 mol %, preferably 2-30 mol %, andespecially 5-20%, relative to the mercaptan.

The reaction can be carried out in the presence of a solvent.

Examples of suitable solvents are alcohols having 1 to 6 carbon atoms,for example methanol, ethanol, propanol, butanol, pentanol or hexanol.However, diols, polyols and ethers thereof can also be used, for exampleglycol, glycerol and polyethylene glycol. The reaction can also becarried out in polar aprotic solvents, for example dimethylformamide ordimethyl sulfoxide, or high-boiling aromatic or aliphatic hydrocarbons,which may be chlorinated, can be employed, for example toluene, ligroinor chlorobenzene. Preferably, dimethylformamide is used which, ifappropriate, is diluted with one of the abovementioned lower alcohols orchlorinated hydrocarbons.

Examples of compounds which form formaldehyde under the reactionconditions are paraformaldehyde or hexamethylenetetramine.

The reactants phenol, formaldehyde and mercaptan can be employed instoichiometric amounts. Sometimes, however, it can be of advantage toemploy an excess of formaldehyde and/or mercaptan. Mixtures of phenolsand/or mercaptans can also be reacted.

The process can be carried out advantageously at temperatures of80°-160° C., preferably 90°-150° C. and especially 90°-130° C. and, ifappropriate, under pressure (for example 0.01 to 5 bar). In the absenceof a solvent, the reaction is preferably carried out under pressure.

The reaction times can vary depending on the specific phenol andmercaptan and are, for example, 1 to 24 hours, in particular 1 to 6hours. Advantageously, the reaction mixture is heated under reflux in anitrogen atmosphere.

All the starting products are known compounds and can be prepared byknown processes. Some of them are also commercially available.

The examples which follow illustrate the invention in more detail.

PREPARATION EXAMPLES EXAMPLE 1 Preparation of2,6-bis-(n-octylthiomethyl)-4-t-butylphenol ##STR7##

A mixture of 22.5 g of 4-t-butylphenol, 18.0 g of paraformaldehyde, 43.9g of n-octanethiol, 4.0 g of 33% ethanolic dimethylamine and 23 ml ofN,N-dimethylformamide is heated under nitrogen for 3 hours under refluxin a sulfonation flask with a reflux condenser and mechanical stirrer.The internal temperature is 110° C.

The crude product is taken up in 150 ml of ethyl acetate and washed with100 ml of water. After evaporation of the organic phase to dryness, thisgives 51 g (97% of theory) of2,6-bis-(n-octylthiomethyl)-4-t-butylphenol as a colourless oil.

Analytical figures: Calculated: 13.74% S Found: 13.44% S.

EXAMPLE 2 Preparation of2,6-bis-(n-octylthiomethyl)-4-(1',1',3',3'-tetramethylbutyl)-phenol##STR8##

The procedure followed is as in Example 1, but using 0.1 mol of4-(1',1',3',3'-tetramethylbutyl)-phenol in place of 4-t-butylphenol.This gives 43.6 g (83% of theory) of the product as a colourless oil.

Analytical figures: Calculated: 12.26% S Found: 12.28% S

EXAMPLE 3 Preparation of2,2-bis-[4',4"-dihydroxy-3',3",5',5"-tetrakis-(n-octylthiomethyl)-phenyl]-propane##STR9##

The procedure followed is as in Example 1, but using the followingmixture: 23.2 g of bisphenol A, 20.4 g of paraformaldehyde, 60.33 g ofn-octanethiol, 7.5 g of 33% ethanolic dimethylamine and 40 ml (38 g) ofN,N-dimethylformamide. The reaction time is 6 hours. The crude productis taken up in methylene chloride and washed with water. This gives 86 g(99% of theory) of the product as a slightly yellowish oil.

Analytical figures: Calculated: 14.89% S Found: 14.87% S

EXAMPLE 4 Preparation of2,2-bis-[4',4"-dihydroxy-3',3",5',5"-tetrakis-(n-dodecylthiomethyl)-phenyl]-propane##STR10##

The procedure followed is as in Example 3, but using an equivalentquantity (in mol) of n-dodecanethiol in place of n-octanethiol. Thisgives 108.9 g (99% of theory) of the product as a yellowish oil.

Analytical figures: Calculated: 11.81% S Found: 11.67% S.

EXAMPLE 5 Preparation of a mixture of the formula ##STR11## in which R₁is n-octyl and/or n-dodecyl.

The procedure followed is as in Example 3, but using a 1:1 mixture of0.2 mol of n-octanethiol and 0.2 mol of n-dodecanethiol in place of 0.4mol of n-octanethiol.

This gives 97.9 g of a slightly yellowish oil. After chromatographicpurification, this gives a yellowish oil which has a flowery odour andwhich, according to HPLC analysis (High Pressure Liquid Chromatography)is a statistical mixture of2,2-bis-[4',4"-dihydroxy-3',3,5',5"-tetrakis-(R₁-thiomethyl)-phenyl]-propanes, R₁ being n-octyl or n-dodecyl.

Analytical figures: (for 2×octyl+2×dodecyl) Calculated: 13.17% S Found:13.21% S.

EXAMPLE 6 Preparation of bis-[4,4'-dihydroxy-3,3',55'-tetrakis-(n-octylthiomethyl)-phenyl]-methane ##STR12##

The procedure followed is as in Example 3, but using the equivalentquantity (in mol) of bisphenol F in place of bisphenol A. Afterextraction with hexane, this gives 76.7 g of an orange-coloured oil.According to ¹ H-NMR spectroscopy (100 MHz, CDCl₃), this contains, inaddition to the named product, also corresponding reaction products ofo,p- and o,o-isomers of bisphenol F as impurities.

Analytical figures: Calculated: 15.39% S Found: 15.28% S.

EXAMPLE 7 Preparation ofbis-[4,4'-dihydroxy-3,3',5,5'-tetrakis-(n-dodecylthiomethyl)-phenyl]-methane##STR13##

The procedure followed is as in Example 6, except that the equivalentquantity (in mol) of n-dodecanethiol is used in place of n-octanethiol.This gives a reddish oil (yield: 93%) which crystallizes in the cold.Melting point 40°-42° C. This time again, the end product contains, inaddition to the named main product, also reaction products of o,p- ando,o-isomers of bisphenol F as impurities.

Analytical figures: Calculated: 12.12% S Found: 12.01% S.

EXAMPLE 8: Preparation of2,2-bis-[4',4"-dihydroxy-3',3",5',5"-tetrakis-(n-octylthiomethyl)-phenyl]-propane##STR14## a) 23.3 g of bisphenol A, 52 g of 40% aqueous dimethylaminesolution and 43.4 g of 36% aqueous formaldehyde solution are heated for18 hours at 75° C. After usual working-up by extraction and drying aswell as recrystallization from ligroin, this gives2,2-bis-[4',4"-dihydroxy-3',3",5',5"-tetrakis-(N,N-dimethylaminoethyl)-phenyl]-propaneas a colourless powder, melting point 91°-93° C. (yield: 94%).

b) 10.72 g of the product obtained under a), 15.1 g of n-octanethiol and0.75 g of powdered potassium hydroxide are heated at 90° C. until aclear solution has formed. At room temperature, 5 ml ofN,N-dimethylformamide are added and the mixture is then heated undernitrogen for 7 hours at 120° C. internal temperature.

After usual working-up, this gives2,2-bis-[4',4"-dihydroxy-3',3",5',5"-tetrakis-(n-octylthiomethyl)-phenyl]-propaneas a slightly yellowish oil (yield: 92.1%).

Analytical figures: Calculated: 14.89% S Found: 15.07% S

EXAMPLE 9 Preparation of 2,6-bis-(n-octylthiomethyl)-4-t-butyl-phenol##STR15## a) 177.7 g of 4-t-butylphenol, 350 ml of 95% ethanol, 266.6 gof 40% aqueous dimethylamine solution and 199.1 g of 36% aqueousformaldehyde solution are heated under reflux for 12 hours. Fractionaldistillation gives 280 g (85% of theory) of2,6-bis-(N,N-dimethylaminomethyl)-4-t-butylphenol as a yellow oil,boiling point 103° C. (at 13.3 Pa).

b) 39.6 g of the compound obtained under a) are heated with 43.9 g ofn-octanethiol for 24 hours at 150° C. under a slight vacuum of about0.53 bar. After purification by column chromatography, this gives 2,6-bis-(n-octylthiomethyl )-4-t-butylphenol as a yellowish oil (yield:69.9 g=98%).

Analytical figures: Calculated: 13.73% S Found: 13.92% S.

EXAMPLE 10 Preparation of2,2-bis-[4',4"-dihydroxy-3',3",5',5"-tetrakis-(2"'ethylhexyloxycarbonyl-methylthiomethyl )-phenyl]-propane ##STR16##

The procedure followed is as in Example 3, but using the equivalentquantity (in mol) of 2-ethylhexyl thioglycolate in place ofn-octanethiol. This gives the product as a yellowish oil (yield: 93.4%).

Analytical figures: Calculated: 11.73% S Found: 11.45% S

EXAMPLE 11 Preparation of 2,6-bis-(n-octylthiomethyl )-4-methylphenol##STR17##

The procedure followed is as in Example 1, but using the equivalentquantity (in mol) of p-cresol in place of 4-t-butylphenol. This givesthe product as a yellowish oil (yield: 99.3%).

Analytical figures: Calculated: 15.10% S Found: 15.03% S

EXAMPLE 12 Preparation of2,6-bis-(2'-ethylhexyloxycarbonyl-methylthio-methyl)-4-t-butylphenol##STR18##

The procedure followed is as in Example 1, but using the equivalentamount (in mol) of 2-ethylhexyl thioglycolate. This gives the product asa yellowish oil (yield: 82.5%).

Analytical figures: Calculated: 11.0% S Found: 10.73% S

Table 1 which follows contains characteristic ¹ H-NMR spectroscopic datafor Examples 1 to 12 (aryl-CH₂ --S signal). The data are given in ppmand relate to the following structures: ##STR19##

                  TABLE 1                                                         ______________________________________                                        Example                                                                       No.     Ar-- .sub.---- CH.sub.2 S**                                                             Structure                                                                              R.sub.1    R.sub.2                                 ______________________________________                                        1        3.80 (s) A        n-C.sub.8 H.sub.17                                                                       t-Butyl                                 2       3.77 (s)  A        n-C.sub.8 H.sub.17                                                                       t-Octyl                                 3       3.73 (s)  B        n-C.sub.8 H.sub.17                                                                       --                                      4       3.73 (s)  B        n-C.sub.12 H.sub.25                                                                      --                                      5       3.73 (s)  B        C.sub.12 H.sub.25 /C.sub.8 H.sub.17                                                      --                                      6       3.75 (s)  C        C.sub.8 H.sub.17                                                                         --                                      7       3.75 (s)  C        C.sub.12 H.sub.25                                                                        --                                      8       3.73 (s)  B        C.sub.8 H.sub.17                                                                         --                                      9       3.80 (s)  A        n-C.sub.8 H.sub.17                                                                       t-Butyl                                 10      3.86 (s)  B        CH.sub.2 COO-2-ethyl-                                                                    --                                                                 hexyl                                              11      3.78 (s)  A        n-C.sub.8 H.sub.17                                                                       CH.sub.3                                12      3.90 (a)  A        CH.sub.2 COO-2-ethyl-                                                                    t-Butyl                                                            hexyl                                              ______________________________________                                         *s = Singlet                                                                  **Ar--.sub.---- CH.sub.2 S = Aryl.sub.---- CH.sub.2S signal              

Application Example Stabilization of polybutadiene rubber (oven ageing)

100 g of polybutadiene, prestabilized with 0.4% of2,6-di-t-butyl-p-cresol, are mixed homogeneously for 6 minutes in a rollmill with 0.25% of 2,6-bis-(n-octylthiomethyl)-4-t-butylphenol fromExample 1. The rolled hides are pressed at 80° C. to give 10 mm thickplates. A further plate is produced in the same way without stabilizer.

The compositions according to the invention are tested by heat-ageing ina circulating-air oven at 80° C. The criterion used is the undesired gelcontent which arises in the course of oven ageing. This is determined inthe following way:

1 g of polybutadiene is dissolved overnight at room temperature in 100ml of toluene. The solution is filtered through a glass suction filter(00 pore size), and the filtered solution is evaporated to dryness.

The gel content is obtained from ##EQU1## E=weight taken (1 g) A=weightof the evaporation residue

After an induction period, the gel content increases rapidly. The timeafter which gel content of 2% is reached is used as an arbitrarydefinition of the induction period. This induction time is determined byperiodic determinations of the gel content.

The measurement shows that the sample which contains the compound fromExample 1 takes an induction time of several weeks, as compared with thesample without stabilizer until the gel content reaches 2%.

What is claimed is:
 1. A composition comprising a lubricant and at leastone compound of the formulae I or/and II ##STR20## in which the radicalsR₁ are identical or different and independently of one another are C₈-C₂₀ -alkyl which is unsubstituted or substituted by 1 or 2 hydroxylgroups or/and interrupted by --O--, or are C₁ -C₄ -alkylene--COOR'₂, C₁-C₄ -alkylene--CO--NR"₂ R₄ or C₅ -C₁₂ -cycloalkyl, R₂, R'₂ and R"₂independently of one another are C₁ -C₂₀ -alkyl, allyl, methallyl,propargyl, C₅ -C₁₂ -cycloalkyl, phenyl or benzyl, R₃ is hydrogen, C₁-C₂₀ -alkyl, C₂ -C₁₈ -alkenyl or halogen, R₄ is hydrogen, C₁ -C₂₀ -alkylor C₂ -C₁₈ -alkenyl, Z₁ is --S--or --C(Z₃)(Z₄)-- and Z₂ is hydrogen, C₁-C₂₀ -alkyl or --CH₂ --S--R₁, Z₃ and Z₄ independently of one anotherbeing hydrogen or methyl, with the proviso that the phenols of theformula II are free of the --CH₂ --S--R₁ functional group in them-position relative to the OH group.
 2. A composition according to claim1, comprising a lubricant and at least one compound of the formulae I orII, in which R₂ is methyl, ethyl or branched C₃ -C₂₀ -alkyl, allyl,methallyl, propargyl or benzyl and R₁, R₃, Z₁ and Z₂ are as defined inclaim
 1. 3. A composition according to claim 1, comprising at least onecompound of the formulae I or/and II, in which the radicals R₁ areidentical or different and independently of one another are C₈ -C₂₀-alkyl or C₁ -C₄ -alkylene--COOR₂ ', R₂ and R₂ ' are C₁ -C₂₀ -alkyl, Z₁is --CH₂ -- or --C(CH₃)₂ -- and Z₂ is as defined in claim
 1. 4. Acomposition according to claim 1, comprising at least one compound ofthe formula I, in which the radicals R₁ independently of one another areC₈ -C₂₀ -alkyl groups, which are unsubstituted, or C₁ -C₂₀ -alkylgroups, which are substituted by 1 or 2 hydroxyl groups.
 5. Acomposition according to claim 1, wherein the radicals R₁ are identicaland are C₈ -C₁₂ -alkyl groups.
 6. A composition according to claim 1,comprising at least one compound of the formula IIa ##STR21## in whichR₁, R₃, Z₁ and Z₂ are as defined in claim
 1. 7. A composition accordingto claim 6, wherein R₃ is hydrogen and Z₁ is --C(Z₃)(Z₄)--.
 8. Acomposition according to claim 6, wherein Z₂ is the radical --CH₂--S--R₁.
 9. A composition according to claim 1, comprising 0.01-10.0% byweight of a compound of the formula I or/and II, relative to thelubricant.
 10. A compound of formula IIa ##STR22## in which the radicalsR₁ are identical or different and independently of one another are C₁-C₂₀ -alkyl which is unsubstituted or substituted by 1 or 2 hydroxylgroups or/and interrupted by --O--, or are C₁ -C₄ -alkylene--COOR₂ ', C₁-C₄ -alkylene--CO--NR₂ "R₄, C₅ -C₁₂ -cycloalkyl, phenyl, 1-naphthyl,2-naphthyl, C₁ -C₄ -alkyl-phenyl or phenyl-C₁ -C₄ -alkyl, R₃ ishydrogen, C₁ -C₂₀ -alkyl, C₂ -C₁₈ -alkenyl or halogen, Z₁ is --S-- or--C(Z₃)(Z₄)-- and Z₂ is hydrogen, C₁ -C₂₀ -alkyl or --CH₂ --S--R₁, withthe proviso that the phenols of the formula II are free of the --CH₂--S--R₁ functional group in the m-position relative to the OH group. 11.A compound according to claim 10, wherein R₃ is hydrogen and Z₁ is--C(Z₃)(Z₄)--.
 12. A compound according to claim 10, wherein Z₂ is a--CH₂ --S--R₁ radical.